Characterization and Quantification of Rat Bile Phosphatidylcholine by Electrospray–Tandem Mass Spectrometry

摘要: Abstract Rat bile phosphatidylcholine was structurally characterized and quantified by electrospray mass spectrometry using a triple quadrupole instrument. All results were obtained direct analysis of an unprocessed total lipid extract from rat bile. Structural characterization achieved collision-induced dissociation [M + Cl] − ions observed in the negative-ion spectrum. Quantification performed positive-ion mode precursor ion scanning m / z 184 dimyristoyl-phosphatidylcholine as internal standard. Using this new methodology, effect cyclosporin A on biliary excretion investigated. After intravenous administration (25 mg/kg body wt) level reduced to about 30% control level. This suggests inhibition translocation across hepatocyte canalicular membrane which is mediated Mdr2 P-glycoprotein.